| OCR Text |
Show RESULTS AND DISCUSSION The Combustion Catalyst Evaluation Program was very successful in reducing excess oxygen and particulate emissions. Particulate emissions, measured by EPA Method 5, were reduced from an average baseline value of 0^14 to 0.09 pounds per million BTU, with the application of a combustion catalyst. The result was 36% reduction in particulate emissions and boiler operation within EPA particulate compliance limits. Field evaluation results are described in Table II. Statistical regression analyses of field data were performed and found that particulate emissions were strong functions of excess oxygen and catalyst feed rate. The multiple regression equation was found to be: Emissions (lb/MMBTU) = 0.0624 + 0.00798 (Percent Excess Oxygen) - 0.0348 (Product Feed rate,lb/T Both particle size and elemental analysis were performed on the sample of particulate collected by EPA Method 5. Particle sizes were measured by scanning electron microscope and almost all the particles were found to be less than 0.3 microns. An electron microscopic x-ray analysis showed a high level of potassium and sulfur in the particulate. As can be seen in Figure 3, small amounts of sodium, silicon, calcium, and zinc were also present. The air heater/dust collector ash sample and bark sample (Table III and I) indicate just the opposite - low levels of potassium and sulfur relative to the other inorganics. This can be explained based on relative volatility of potassium, with respect to others. Potassium has a partial vapor pressure of 760 mm of mercury at 1418°F, as compared to calcium, whose partial pressure is only 1 mm of mercury. Therefore, volatilization of potassium at high furnace temperatures and then reacting with sulfur compounds to form potassium 2.5.10 |
